Method of manufacturing piercer plug
A piercer plug having good base-material deformation resistance is provided. A method of manufacturing a piercer plug ( 10 ) includes the steps of; preparing a plug body ( 1 ) including a tip portion ( 11 ) and a cylindrical portion ( 12 ) having a hole ( 121 ) usable to attach a bar and located rearward of the tip portion ( 11 ); forming a build-up layer ( 2 ) on the surface of the tip portion ( 11 ); and heating the plug body ( 1 ) such that the temperature of the tip portion ( 11 ) with the build-up layer ( 2 ) formed thereon is not lower than the austenite transformation temperature and the temperature of the cylindrical portion ( 12 ) is lower than the austenite transformation temperature.
1. A method of manufacturing a piercer plug comprising the steps of:
preparing a plug body including a tip portion and a cylindrical portion having a hole usable to attach a bar and located rearward of the tip portion;
forming a build-up layer on a surface of the tip portion; and
heating the plug body such that a temperature of the tip portion with the build-up layer formed thereon is not lower than an austenite transformation temperature and a temperature of the cylindrical portion is lower than the austenite transformation temperature,
the build-up layer being formed of an Ni—W alloy containing 25 to 50 mass % W and 1 to 5 mass % Cr.
2. The method of manufacturing the piercer plug according to claim 1 , further comprising the step of forming a sprayed coating on a surface of the plug body with the build-up layer formed thereon before the step of heating.